Reflecting lamp



H. A. DOUGLAS. REFLECTING LAMP. APPLICATION FILED APR-4. 1917.

. LQUQBSQQBI Patented Jan. 10?, 1922.,

Z SHEETS-SHEET I.

H. A. DOUGLAS.

REFLECTING LAMP.

APPLICATION FILED APR. 4. 1917.

1,46%} 4 1 Patented Jan. MP, 1922.

2 SHEETS-SHEET 2.

STATES HARRY A. DOUGLAS, F BRONSON, MICHIGAN.

REFLECTING LAMP.

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Application filed April 4,

clear, concise, and exact description.

My invention relates to reflecting lamps of that class employing concave casing and a concave reflector which are spaced apart at the rear of the lamp structure. In practicing my invention I employ a tubular holder which is engaged with either the casing or the reflector and preferably with both of these elements, and when connected with both'of these elements the holder is of service in assembling the reflector and casing at the rear ends thereof, to which end the holder is desirably provided with a forward flange and a rear flange, the rear flange being preferably in the' form of a nut which is in threaded engagement with the complemental portion of the holder whereby the pressure with which the holder engages the reflector and casing is regulable. A tubular shell is disposed in the holder, a lamp bulb being carried at the forward end of the shell. This shell is desirably movable longitudinally of the holder to secure focal adjustment of the bulb and preferably terminates at the rear of the casing to be accessible for its movement. The rear end of the shell desirably carries a plug by which the lamp is included in circuit. This plug may be in the form of a switching plug when it should have alternative positions for including the lamp in circuit and excluding it from circuit.

I will explain my invention more fully by reference to the accompanying drawings showing preferred embodiments thereof and in which Fig. 1 illustrates a construction wherein the tubular holder acts to maintain the rear ends of the concave reflector and concave casing in assembly; Fig. 2 is a view, on a larger scale, of a part of the structure shown in Fig. 1, portions appearing in section on line 2-2 of Fig. 1 and other portions in elevation; Fig. 3 is a View on line 33 of Fig. 2; Fig. 4 is a view on line 4-4 of Fig.

2; Fig. 5 shows a construction wherein the tubular holder does not engage the casing,

the holder being positioned by reason of its Specification of Letters Patent.

Patented Jan. 10 11922.

1917. Serial No. 159,729.

engagement with the reflector; Fig. 6 is a v1ew on line 6-6 of Fig. 5; and Fig. 7 is a perspectlve view of the bulb holding shell, as it is preferably constructed.

Like parts are indicated by similar char-. acters of reference throughout the different figures.

The concave reflector 1 is received in a concave reflector carrying casing 2 and is spaced apart therefrom.. A. rearwardly extending tubular continuation 3 that is coaxial with the reflector virtually constitutes a continuation of the reflector 1, in both forms of the construction. In both forms of the invention the front end of the tubular holder is provided with a flange 3 In the form of the invention shown in Figs. 1 and 2 the rear end of the holder is provided with a flange 3 that is-preferably in the form of a nut in threaded engagement with the complemental portion of the holder. The reflector and casing (Figs. 1 and 2) are disposed between these flanges and the pressure with which the flanges engage these elements is regulated by the nut 3 Where the holder does not extend to and through the casing 2 but terminates short thereof, as in the construction shown in Figs. 5 and 6, the holder 3 is engaged with the reflector by being provided with a flange 3 which is closely approached to the flange 3 the rear end of the reflector being clamped between the flanges 3 and 3 A spring tongue 4 is integrally formed with a shell 5 that constitutes a holder for contact carriers, this spring tongue having ample clearance at its side margins to permit it freely to function. Some part of the tongue, preferably the rear free end thereof, has a part 6 projecting therefrom which is narrower than the balance of the tongue and is slightly narrower than a slot 7 in the holder 3 whereby this portion may project into the slot to prevent the shell from turning with respect to the slot while at the same time the side margins of the tongue 4 are adapted to press against the side margins of the slot 7. The tongue thus presses upon a surface of the holder 3 and, Where there is but one tongue, forces the shell toward the opposite side of the holder whereby the shell is held in engagement with the holder 3. The slot 7 is elongated so that the shell 5 may be moved back and forth in its holder 3 whereby in the structure illustrated the position of the lamp bulb 8 which is carried by the forward end of the shell in front of the reflector may be adjusted with respect to the reflector, the spring tongue acting as a means for maintaining the shell in adjusted positions with respect to the holder, this means permitting focal adjusting movements of the shell. The base 9 of the lamp bulb 8 constitutes the forward contact carrier and asthe arrangement illustrated is a double pole arrangement this contact carrier 9 carries two rear contacts 10 and 11. The lampbase or contact carrier 9 is provided with bayonet pins 12 engageable within bayonet seats 13 constituting parts of bayonet slots 14. As the shell 5 desirably terminates at the rear end of the casing 2 and is there preferably provided with a connecting plug which is also desirably a switching plug, I provide an inner contact carrying plug 15 that is located at an intermediate portion of the shell where it is preferably fixed with respect to the shell. This plug, which is of insulating material, carries metallic current conductingspring barrels 16 that extend therethrough. These spring barrels contain springs 18, one spring extending into the hollow contact 20 and the other into the contact 17. The inner ends of these contacts are enlarged into heads and the ends of the barrels 16 are inturned whereby the spring barrels and their engaging contacts are maintained in assembly. The contacts 19 and 20 carried by the inner contact carrier normally permanently engage the contacts 10 and 11 while the contacts 17 also carried by the inner contact carrier respectively engage the contacts 10 and 11 upon the plug 15 at the rear end of the shell whereby the lamp is included in circuit.

The plug or contact carrier 15 is preferably rotatable within the rear end of the shell 5 (this rear end of the shell terminating at the rear end of the casing 2, and desirably projecting to some extent beyond the rear of the casing) to which end the contact carrier or plug 15 is provided with bayonet pins 21 that are receivable in alternate bayonet seats 22, 23 of av bayonet slot. The springs 18 thus not only serve to hold the bayonet pins 12 in their seats but also serve to hold the bayonet pins 21 in the seats to which they are adjusted.

It will be observed that the complemental switching contacts 10 and 17 are eccentric with respect to the shell as are also the complemental switching contacts 11 and 17 so that as the plug 15 is turned these complemental contacts are either brought into engagement or separated according to the direction of rotary movement of the plug 15 Vhen the lamp is in open circuit the contacts 17 are pressed against the insulating portions of the plug 15 the springs continuing to press the contacts 17 rearwardly to maintain the bayonet pins 21 in the seats to which they are adjusted. The plug may have a globular knurled member 15 that operates to protect the current conductors from having chafing contact with the rear of the plug and which may be grasped when the plug is to have its position changed to cut the lamp in or out of circuit. The lamp bulb may be focally adjusted by pulling or pushing upon the shell 5 directly accordingly as the lamp is to be moved rearwardly or forwardly, or these movements of the shell may be effected with the aid of the knurled member 15 which may be grasped and pulled upon or pushed upon to effect corresponding movements of the shell and the lamp bulb at its front end.

It will be further observed that as a result of my present structure the narrow part 6 of spring tongue 4:, by its engagement with the rear wall of slot 7, acts to limit outward sliding movement of the shell beyond a predetermined point, so that the liability of the bulb 8 coming in contact with the reflector and thereby becoming broken is eliminated. When slidably adjusting the shell forwardly, however, there is a possibility of the spring tongue and part6 thereof riding over the forward wall of the slot 7 and thereby allowing the lamp bulb to move dangerously too far forward, and for this reason the plug 15 is provided with a portion such as thehead illustrated thereon which is designed to contact with the outer end of the 100 holder to thereby limit inward movement of the shell.

While I have herein shown and particularly described the preferred embodiment of my invention I do not wish to be limited to 105 the precise details of construction shown as changes may readily be made without departing from the spirit of my invention, but having thus described my invention I claim.as new and desire to secure by Let- 11 tens Patent the following In a reflecting lamp, the combination with a casing having a reflector therein, of a tubular holder extending through the casing and reflector, means carried by the holder 115 and engageable with the casing and reflector and coacting with the holder to bind the casing and reflector together in relative spaced relation, said tubular holder being entirely open at its ends and of constant in- 12 ternal diameter throughout its length, a shell disposed within the holder and projecting beyond the outer open end of the latter, and at its inner end being adapted to receive a lamp bulb, said shell being lon- 12E gitudinally slidable in the holder to effect focal adjustments of a lamp bulb carried thereby with respect to the reflector, means preventing relative rotation of the holder and shell and acting to limit outward slid- 130 with the outer end of the holder to limit inward sliding movement ofthe shell beyond a predetermined point. 10

In Witness whereof, I hereunto subscribe my name this 28th day of February, A. 1D.

HARRY A. DOUGLAS. 

